Editing board file

i open my board.txt file wanted to edit but i couldn't find this line
"mega2560.upload.protocol=wiring".
any help or suggestions

What do you want to change it to?
This is what I have in 1.8.13 boards.txt

## Arduino Mega w/ ATmega2560
## -------------------------
mega.menu.cpu.atmega2560=ATmega2560 (Mega 2560)

mega.menu.cpu.atmega2560.upload.protocol=wiring
mega.menu.cpu.atmega2560.upload.maximum_size=253952
mega.menu.cpu.atmega2560.upload.speed=115200

mega.menu.cpu.atmega2560.bootloader.high_fuses=0xD8
mega.menu.cpu.atmega2560.bootloader.extended_fuses=0xFD
mega.menu.cpu.atmega2560.bootloader.file=stk500v2/stk500boot_v2_mega2560.hex

mega.menu.cpu.atmega2560.build.mcu=atmega2560
mega.menu.cpu.atmega2560.build.board=AVR_MEGA2560

Are you sure that you are looking at the active boards.txt file?
I have several relics from old installations, in different places, which I have not yet cleaned up. Does the date look reasonably fresh?